If the bulbs do not fix the problem, then most likely the ballast is burned out. I just fixed mine by replacing the bulbs with LED’s light tubes which should be the last time I have to work on this fixture. I attached a few photos to show the work and the burned ballast. I used 12-inch waterproof LED light tubes from super bright LEDs. LT series 7inch & 12inch SMD LED Light Tubes Specifications Brad 2000 U320
I finally succeeded in replacing fluorescent tubes with LEDs in our porch light.
Yesterday morning I began the final installation by attaching the light fixture to the side of the motorhome. Once everything was in place I hooked up the wires and flipped the switch and…………. nothing happened. I knew the wires were hot. Upon closer examination, the hot wire had become separated from one of the splices I made yesterday. I hate it when that happens. Then the project went south.
I determined that I would have to connect new and longer wire leads inside of the coach and push them through the dime-sized hole in the outer wall. But stupid me thought that the hole on the outside of the motorhome was in an exact straight line with the hole inside of the cabinet. So I pulled the one remaining length of old wire completely into the inside of the coach. Well, crap. It was not in a straight line. In fact, the outside hole was five inches higher than the inside hole and there was only a 1/4 inch gap between the walls for me to fish new wires in place. I used a long piece of solder — stiff enough to push, but soft enough to grab hold of with small needle-nose pliers, and with Sandy’s great help we got it done.
George Stoltz 2000 U320